Field of the Invention
The present invention relates to an image forming apparatus.
Description of the Related Art
Hitherto, the following image forming apparatus exists. Specifically, when a currently conveyed sheet is jammed and cannot be conveyed any more, the image forming apparatus stops all the currently conveyed sheets including the sheet causing the sheet jam and displays an operation guidance for jam removal so as to urge a user to cope with the sheet jam.
However, a sheet without damage such as a fold, which has not been subjected to image formation with a toner, is required to be removed by the user when the sheet jam occurs even though the sheet is reusable. As a result, there arises a problem in that the usable sheet is wasted.
In view of the problem described above, the following technology has been proposed. According to the technology, when the sheet jam occurs, a reusable sheet that is closer to a sheet feeding device than the jammed sheet and has not been subjected to the image formation is returned to the sheet feeding device by reverse rotation of conveyance rollers (Japanese Patent Application Laid-Open No. 2010-070288).
When the sheet is returned to the sheet feeding device, however, the returned sheet is sometimes damaged depending on the amount of return of the sheet or a configuration of the conveyance rollers configured to return the sheet. For example, it is assumed that the sheet fed from the sheet feeding device is stopped in a state in which a center portion of the sheet is nipped between rollers of a sheet feeding roller pair and a leading edge of the sheet is nipped between rollers of the conveyance roller pair provided downstream of the sheet feeding roller pair when the sheet jam occurs. The sheet feeding roller pair can rotate reversely to convey the sheet in a direction of returning the sheet to the sheet feeding device. However, the conveyance roller pair provided downstream of the sheet feeding roller pair cannot rotate reversely so as to convey the sheet in the direction of returning the sheet to the sheet feeding device. Therefore, when the sheet feeding roller pair is rotated reversely so as to convey the sheet in the direction of returning the sheet to the sheet feeding device in a state in which the sheet is nipped between the rollers of the sheet feeding roller pair and the rollers of the conveyance roller pair provided downstream of the sheet feeding roller pair, a roller mark of the conveyance roller pair is sometimes left on the sheet. When the sheet damaged with the roller mark is used for the image formation, there is a possibility of occurrence of an image defect or conveyance failure.